KR101281860B1 - Control valve for a device for variably adjusting the valve timing for gas exchange valves in an internal combustion engine - Google Patents

Abstract

The present invention relates to a control valve (14) for an apparatus (1) for changing the valve timing of gas exchange valves (110, 111) in an internal combustion engine (100). According to the invention, a check valve 54 is arranged inside the annular groove 44 formed in one of the components of the control valve 14 and through which the pressure medium flows. The object of the present invention is to reduce the assembly costs in particular.

Internal Combustion Engine, Gas Exchange Valves, Control Valves, Annular Grooves, Check Valves

Description

CONTROL VALVE FOR A DEVICE FOR VARIABLY ADJUSTING THE VALVE TIMING FOR GAS EXCHANGE VALVES IN AN INTERNAL COMBUSTION ENGINE}

The present invention relates to a control valve for a device for variably adjusting the valve timing of gas exchange valves in an internal combustion engine in accordance with the preamble of claim 1 or 6, and in an internal combustion engine according to the preamble of claim 13 or 16. TECHNICAL FIELD The present invention relates to the use of a check valve disposed in an annular groove for circulation of a pressure medium of an apparatus for varying the valve timing of gas exchange valves.

Camshafts are used to operate gas exchange valves in an internal combustion engine. In an internal combustion engine, the camshafts are constructed in such a way that the cams mounted on the camshaft itself are adjacent to the cam followers, for example a bucket type tappet, a finger type rocker, or a rocker arm. Is mounted. As the camshafts rotate and displace, the cams roll in the cam followers so that the cam followers actuate the gas exchange valves. Therefore, by the position and shape of the cams, the opening amplitude as well as the opening amplitude of the gas exchange valves and their opening and closing timings are determined.

During operation of the gas exchange valves, the valve springs exert an alternating moment on the camshaft by applying force to the cams of the camshaft.

The modern engine concept is to design the valve drive in a variable manner. On the one hand, the valve lift and the valve opening period must be implemented variably until the individual cylinders are completely deactivated. For this purpose, concepts such as a switchable cam follower, an electrohydraulic valve actuating device, or an electric valve actuating device are provided. It has also been found to be desirable to be able to influence the opening and closing times of gas exchange valves during operation of the internal combustion engine. In this regard, it is particularly desirable to be able to individually influence the opening and closing points of the intake valves or exhaust valves, respectively, for example in order to adjust the defined valve overlap as intended. Depending on the actual characteristic area of the engine, for example by adjusting the opening or closing points of the gas exchange valves according to the actual rotational speed or the actual load, the inherent fuel consumption is reduced, positively affecting the exhaust gas behavior, the engine efficiency, The maximum torque and maximum output can be raised.

The variability described for the valve timing of the gas exchange valve is achieved by changing the phase position of the camshaft relative to the crankshaft. In this regard, the camshaft is connected with the crankshaft in a manner that is usually driven through a chain drive, belt drive, toothed gear drive, or actuating concepts. Between the chain drive, belt drive, or toothed gear drive driven by the crankshaft and the camshaft, a device for variably adjusting the valve timing of the gas exchange valves in the internal combustion engine is mounted, which device is described below. It is referred to as an adjusting device. Such camshaft adjusting devices usually transmit rotational torque from the crankshaft to the camshaft. In this regard, the phase position between the crankshaft and the camshaft remains fixed while the internal combustion engine is in operation, and, if necessary, in such a way that the camshaft can be rotated opposite the crankshaft in a predetermined angle region. The device is configured.

In an internal combustion engine having respective camshafts for intake valves and exhaust valves, the camshafts may be provided with respective camshaft adjusting devices. By doing so, the opening and closing points of the intake and exhaust gas exchange valves can be temporarily changed relative to each other, and the valve overlap can be adjusted as desired.

The seat of a modern camshaft adjustment device is usually located at the drive side end of the camshaft. However, the camshaft adjusting device may be disposed on the intermediate shaft, the non-rotating structural member, or the crankshaft. The camshaft adjusting device includes a drive wheel which is driven by the crankshaft and maintains a fixed phase relationship with the crankshaft, a driven member connected to the camshaft in a driven manner, and an adjustment that transmits the rotational torque of the drivewheel to the driven member. It consists of a mechanism. The drive wheel may be formed as a chain wheel, a belt wheel or a toothed wheel when the camshaft adjusting device is not disposed on the crankshaft, and may be connected to the crankshaft using a chain drive, a belt drive, or a toothed gear drive. Driven by. The adjusting mechanism can be operated electrically, hydraulically or pneumatically.

Two preferred embodiments of the hydraulically adjustable camshaft adjusting device are the so-called axial piston adjusting device and the rotary piston adjusting device.

In the case of an axial piston adjustment device, the drive wheel is connected with the piston via a helical gear, and the piston is also connected with the driven member via the helical gear. The piston separates the hollow chamber formed by the driven member and the drive wheel into two pressure chambers disposed axially with each other. Thus, if one pressure chamber is supplied with a pressure medium, while the other pressure chamber is in communication with the tank, the piston is displaced axially. The axial displacement of the piston rotates the drive wheel relative to the driven member via helical gears, thus also rotating the camshaft relative to the crankshaft.

The second embodiment of the hydraulic camshaft adjusting device is a so-called rotary piston adjusting device. In this case, the drive wheel is fastened in rotation with the stator. The stator and the drive member (rotor) are arranged concentrically with each other, and the rotor is forcedly coupled, formally coupled, or materially coupled, for example, using press fit, screw or weld fastening, camshafts, camshaft extensions, Or with an intermediate shaft. In the stator, a plurality of recesses arranged in the circumferential direction are formed. These recesses extend from the rotor and extend outward in the radial direction. The recesses are scoped in a high pressure sealed manner by side covers in the axial direction. The wing connected to the rotor extends to distribute two pressure chambers into each of the recesses. Thereby, two groups of pressure chambers are formed. The pressure chamber of one group communicates with the hydraulic pump and the pressure chamber of the other group as desired with the tank, so that the phase of the camshaft relative to the crankshaft can be adjusted or fixed. The wings may be formed integrally with the rotor, for example, or may be formed as separate structural members disposed in a wing groove extending axially from the outer surface of the rotor and tightly contacted radially outwardly using a spring member. It may be.

To control the camshaft adjustment device, the sensors detect engine characteristic data, such as the actual phase position, load state, and rotational speed of the camshaft relative to the crankshaft. The data is supplied to an electronic control unit which controls the supply and discharge of pressure medium to the various pressure chambers after comparing the data with the characteristic data field of the internal combustion engine.

In order to adjust the phase position of the camshaft against the crankshaft, in the hydraulic camshaft adjusting device, the pressure chamber on one side of the two interacting pressure chambers is in communication with the hydraulic pump, and the pressure chamber on the other side is in communication with the tank. The supply of the pressure medium consisting of one chamber in conjunction with the discharge of the pressure medium from the other chamber displaces the piston / wings separating the pressure chambers, whereby the axial displacement of the piston in the axial piston adjustment device Using the gears the camshaft is rotated relative to the crankshaft. In the case of the rotary piston adjusting device, by applying pressure to the pressure chamber of one group and reducing the pressure in the pressure chamber of the other group, circumferential displacement of the wing is caused, thereby directly rotating the camshaft with respect to the crankshaft. This is caused. To fix the phase position, the two pressure chambers are in communication with the hydraulic pump or separated from the tank as well as the hydraulic pump.

Control of the pressure medium flow to the pressure chambers is done using a control valve, usually using a 4/3 proportioning valve. Such a control valve consists essentially of a valve housing, a control piston, and an actuating unit formed in a hollow cylindrical shape. The valve housing has a respective connection (work connection) for each group of pressure chambers with the same function, a connection to the hydraulic pump, and at least one connection to the tank. These connections are usually formed as annular grooves on the outer surface of the valve housing, which annular grooves communicate with the inside of the control piston via radial openings. Inside the valve housing, a control piston is disposed axially displaceable. The control piston can be positioned at each position between the two defined final positions in the axial direction against the spring force of the spring member, usually using an electromagnetic or hydraulically actuated operating unit. The outer surface of the control piston essentially corresponds to the inner diameter of the valve housing and has annular grooves and control edges. By controlling the operating unit, the individual connections can be in hydraulic communication with one another, whereby the individual pressure chambers can be connected with the hydraulic pump or tank alternatively. Likewise a position of the control piston in which the pressure medium chambers are separated from the pressure medium tank as well as the hydraulic pump can be provided.

The control valve is known from JP 07-229408A. In this case, on the outer surface of the valve housing, five annular grooves are formed spaced apart from each other in the axial direction, each annular groove being used as a connection portion of the valve. A groove opening is formed in the groove bottom of each of the annular grooves. This radial opening joins into the interior of the valve housing. The openings of adjacent groove bottoms are then offset by 180 ° from each other in the circumferential direction.

Inside the valve housing, a control piston formed of solids is arranged. This control piston can be positioned between the two end stops in the axial direction against the force of the spring inside the valve housing using an electromagnetic actuating unit. The outer diameter of the control piston corresponds to the inner diameter of the valve housing. In addition, three annular grooves are formed in the control piston, and adjacent connections may be communicated with each other through the annular grooves depending on the position of the control piston relative to the valve housing.

Further embodiments of such control valves are known from DE 198 53 670 A1. This control valve is distinguished from the embodiment shown in JP 07-229408A in that the control piston is formed hollow. In addition, only three connections are formed on the outer surface of the valve housing, and the fourth connection is formed in the axial direction of the valve housing. The pressure medium can be guided through the axial feed connection to the working connection on one of the two working connections depending on the respective position of the control piston relative to the valve housing. At the same time each other working connection is in communication with the tank connection via an annular groove formed on the outer surface of the control piston. In the case of such a control valve, the position of the supply connection and the tank connection can be exchanged.

By causing the camshafts of the camshaft to move in rolling contact on the cam follower of the valve drive, a periodic alternating moment acts on the camshaft. This alternating moment is transmitted on the rotor of the camshaft adjustment device, whereby a pressure peak occurs in the pressure chambers. Check valves are provided between the control valve and the hydraulic pump to suppress such pressure peaks from passing through the pressure medium lines and the control valve to the pressure medium circulation system of the internal combustion engine. In this regard, a separate check valve may be provided, or a check valve integrated in the control valve may be provided. The check valve integrated in the control valve is for example shown in EP 1 291 563 A2. In this embodiment, inside the annular groove formed in the valve housing, a sealing member consisting of a band curved by a ring is arranged. The annular groove is bounded by the sleeve in the radial direction. In addition to the sleeve, openings are formed in the groove bottom of the annular groove, through which the pressure medium can reach the interior of the valve housing. The band is also made of spring steel and is preloaded from the radial direction to the outward direction.

If the pressure inside the valve housing exceeds the pressure of the pressure medium present in the opening of the sleeve, the band is adjacent to the inner surface of the sleeve, thereby inhibiting the flow of pressure medium from the inside of the valve housing to the opening of the sleeve. . In the opposite case, the band is pressed inwardly by the pressure medium present in the opening of the sleeve, whereby the pressure medium can be guided from the opening of the sleeve into the valve housing.

This variant of the check valve, which saves construction space, is associated with the disadvantage that assembly in adjacent parts can be very complex and easily broken, based on the preload of the band from radial to outward. Since the annular grooves must be sealed in the assembled state opposite the adjacent parts, the outer diameter of the valve housing corresponds to the inner diameter of the adjacent parts, and the valve housing is integrated into the adjacent parts using a loose fit. In this connection, the band preloaded in the radial direction outwards tries to extend outward, so that the band protrudes from the annular groove. The band may be damaged during assembly or may be sandwiched between adjacent components and the valve housing. This makes functional safety of the check valve or the entire control valve problematic.

According to an alternative embodiment, the band forming the closure body is arranged inside an annular groove formed in the inner surface of the valve housing. In this regard the band is preloaded from radial to outward. As the hydraulic medium enters the valve housing, the band is curved radially inward, otherwise the band is adjacent to the groove bottom of the annular groove and thus receives an outwardly directed pressure medium flow. Block it. However, in this embodiment the complex assembly of the closure body works undesirably. In addition, there is a risk that the band is caught in the area of the control piston which is displaceably disposed inside the valve housing and thereby suppresses the positioning of the control piston.

It is therefore an object of the present invention to avoid the above mentioned disadvantages in the prior art and, accordingly, in a control valve for a device for variably adjusting the valve timing of gas exchange valves in an internal combustion engine, a check valve in the pressure medium circulation system of the camshaft adjustment device. Or to provide the control valve integrated into the control valve surface or in the control valve. Another object of the present invention is to ensure that the check valve is not damaged during assembly or the function of the control valve is not degraded. The present invention also aims to reduce the assembly cost of the control valve and thus its manufacturing cost for further purposes.

A control valve for a device for variably adjusting the valve timing of gas exchange valves in an internal combustion engine, comprising: a valve housing disposed inside an adjacent component and a control piston disposed inside the valve housing, the two structural members being the valve housing and the control; Formed in at least one structural member of the piston, the control piston having a groove extending in the circumferential direction of the structural member and flowing through the pressure medium, a hermetic body disposed in the groove, a valve housing and an adjacent part, respectively; In the case of the first embodiment of the control valve comprising at least one opening for communicating the groove with the pressure medium line, the closure valve and the opening interacting as a check valve. A spring member for the valve to close the sealing body in the direction of the opening It is achieved by not included.

In this regard, the closure body can only be moved towards the opening only by the flow of the pressure medium during the closing process of the check valve.

The outer surface of the valve housing is arranged with a plurality of annular grooves axially spaced from each other. These annular grooves communicate with the interior of the valve housing through openings formed in the groove bottom. With the control valve assembled, the annular grooves are constrained by adjacent parts, such as by camshaft, wall of the cylinder head, or sleeve, from radial to outward direction. Within its wall, which confines the annular grooves in the adjacent part, one opening is provided per annular groove which communicates the annular grooves with each pressure medium line. In addition, the groove bottoms of the annular grooves are likewise provided with openings, through which the annular grooves communicate with the inside of the valve housing. The pressure medium can thereby be guided from the hydraulic pump into the valve housing through an annular groove which serves as a supply connection. In addition, through the other annular grooves, the pressure medium can reach various groups of its pressure chambers which have the same function in the camshaft adjusting device.

In order to prevent pressure peaks occurring in the pressure chambers of the camshaft adjusting device from reaching the pressure medium circulation system of the internal combustion engine through the supply connection, a check valve is arranged inside the annular groove used as the supply connection. The check valve is composed of a rigid closure body disposed displaceably in the radial direction of the valve housing and an opening provided in the wall portion of the adjacent part used as the valve seat. If the system pressure created by the hydraulic pump exceeds the pressure present inside the valve housing, the closure body moves inward in the radial direction, thus directing the pressure medium flow from the opening in the adjacent part into the valve housing. Allow. In this regard, the closure body moves radially until it is adjacent to the groove bottom of the annular groove without restoring force of the spring.

If the pressure medium flow is set in the opposite direction, the pressure medium flows on the back side of the closure body, whereby the closure body is pressed in the radial direction outward, ie toward the valve seat. In this regard, the opening and the closure body are formed such that the closure body can be adjacent to the opening in such a way that the pressure medium flow from the valve housing to the pressure medium line is blocked.

According to an alternative method, the closure body can be arranged inside an annular groove formed in the control piston and in direct communication with the supply connection. In this case, only one opening is formed in the groove bottom of the annular groove used as the supply connection. It is likewise possible to form a plurality of openings in such a way that they are closely spaced from one another at limited surface intervals.

By arranging the check valve in the annular groove of the control valve, the control valve is particularly preferably positioned at the position as close as possible to the position of generation of the pressure peak. This provides a stronger hydraulic support. In addition, no additional configuration space for a separate check valve is required. By providing the check valve with a sealing member which is not operated by the spring member, the assembly of the check valve is greatly facilitated. The closure member is positioned inside the annular groove, and then the structural member is joined. There is no danger that the sealing body protrudes. In addition, by forming the check valve to operate fluidly, a simple and economical structure is allowed, and the original design of the control valve can be maintained.

According to a preferred refinement of the invention, at least one guide member is formed in the closure body. The guide member interacts with at least one guide surface formed in the structural member comprising the groove. In addition, a closure body can be provided, and the structural member comprising the groove can be formed in such a way that the closure body can only be assembled in a specified orientation.

At least one guide member is formed in the closure body to ensure that the closure body is always oriented in the radial direction towards the opening, and that movement of the closure body can only be made in the oriented direction. The guide member (s) interact with the valve housing while preventing the closure body from rotating inside the annular groove.

Such a guide function can be implemented, for example, by forming two guide webs. The guide webs and the closure body are then shaped in a U shape, and the guide web is adjacent to the groove bottom. According to this embodiment the groove bottom is preferably provided with respective flattening in the areas where the guide webs are adjacent. By thus forming the closure body and the valve housing, on the one hand the positional assignment of the closure body relative to the valve seat in a function-safe manner is achieved, and the risk of causing orientation errors of the closure body during assembly is minimized.

If additionally the two horizontal straightening parts of the annular groove of the valve housing are formed at an angle greater than zero rather than parallel to each other, and at the same time the guide webs are provided in conformity with such a shape, the sealing body has one side It is achieved that only the orientation of, ie only in the correct orientation, can be ensured, thereby ensuring the functional safety of the check valve.

A further possibility of forming the guide member in the closure body lies in, for example, forming a journal in the center of the blocking member of the closure member. This journal portion is inserted into and engaged with one of the openings provided in the groove bottom of the annular groove.

Preferably, the sealing body is formed with a fixing member for fixing the sealing body inside the groove.

By forming the fixing members in the sealing body or the guide members of the sealing body, the sealing body is prevented from being lost before assembling the control valve. The securing members can be formed, for example, as latch noses in the guide webs. These latch nose portions at least partially surround the valve housing on the side facing away from the closure body. In the case where the journal portion is disposed centrally, the fastening members may be formed as beads that are provided circularly around their ends facing in the opposite direction of the blocking member in the journal portion.

By forming the fixing members, the closure body is not lost on the one hand when assembling the valve or during transportation. On the other hand, forming the fastening members accordingly prevents the sealing body from extending beyond the annular groove during assembly of the valve to the adjacent part.

By incorporating a check valve in the control valve and securing the closure body inside the annular groove, no additional cost is incurred during final assembly.

A control valve for a device for variably adjusting the valve timing of gas exchange valves in an internal combustion engine, comprising: a valve housing disposed inside an adjacent part and a control piston disposed inside the valve housing, the valve housing having a circumference of the valve housing; Further to said control valve, said control piston having an annular groove extending in a direction and flowing through the pressure medium, and a check valve disposed in said annular groove having at least one hermetically shaped body. In the case of an embodiment, the object according to the invention is that the check valve continues to comprise a frame conforming to the shape of the annular groove, in which the end of at least one sealing body is received, and also the closing of the sealing body. Achieved by providing at least one stop that limits the movement The.

According to this embodiment, inside the annular groove used as the supply connection in the control valve, an annular frame made of a rigid material which can only be bent slightly is arranged. In this regard, the axial extension of the frame corresponds to the axial extension of the annular groove. The frame is formed in such a way that at least one cavity is provided between two annular sections formed at the axial end of the frame. Thereby the pressure medium can reach the annular groove from the opening in the adjacent part. If a plurality of cavities are provided, these cavities are separated from each other by braces extending essentially in the axial direction.

At least one flexible sealing member is arranged inside the frame. One end of the closure member is received by the frame, the dimensions of the closure member being selected in such a way that it can cover the entire area of the recess portion (s). The frame is preferably made of plastic and can be produced, for example, by an injection molding method. In this case, the coupling between the closure body and the frame can be realized by partially injecting the closure body around during the manufacturing process of the frame. According to an alternative method, by forming a shape coupling member, it is possible to provide a shape coupling between two components.

If the system pressure provided from the hydraulic pump exceeds the pressure inside the valve housing, the flexible closure body curves from radial to downward. By doing so, the closure body opens the path for the pressure medium, which can be introduced from the outside into the annular groove and fed to the variable adjustment device for the valve timing. When the pressure medium flows in the opposite direction, the flexible closure body is in tight contact radially outward until it is adjacent to the frame and / or braces. This closed movement can be further assisted by the closure body being made of elastic material.

An advantage of this embodiment is that the check valve can be simply assembled in the annular groove and is accommodated in the annular groove without loss after assembly. The check valve is preferably formed in a ring shape and has two ends open opposite to each other in the circumferential direction. These open ends can be fastened to each other using a clip fastening, or a similar fastening method. Another advantage is that neither the frame nor the closure body protrudes beyond the edge of the annular groove. Doing so ensures a simple and functionally safe assembly of the control piston in the valve housing or a simple and functionally safe assembly of the valve housing in adjacent parts.

According to a preferred refinement of the invention, the closure body consists of a ring-shaped band which extends in the circumferential direction and a ring-shaped axial end of the closure body is received in the frame. The band consists of a silicone sealing lip according to a preferred embodiment. This sealing lip is injection molded directly into the frame using a two-component injection molding process.

Perfusion of the hydraulic medium passing through the check valve can be increased by forming a plurality of cavities arranged in the frame spaced apart in the circumferential direction. In this case the closure body is formed as a band that is curved in the shape of a ring, and the axial end of the ring-shaped band is received inside the frame. Adjacent cavities of the frame are separated from each other by axially extending braces, which simultaneously serve to delimit the path of the closure body from radial to outward.

In addition, two sealing bodies can be provided which are arranged offset from each other in the axial direction. In this connection each end of each closure body is received in a frame, and the received end is each end facing in the opposite direction from the other closure body. In this case, the two closure bodies can be arranged and formed in an axially overlapping manner with the check valve closed.

By using two hermetic bodies arranged in at least partially overlapping manner in the closed state, turbulence during perfusion of the hydraulic medium and thus hydraulic resistance can be reduced. By overlapping the sealing bodies in the closed state, the ring-shaped contact surfaces of the sealing bodies to each other are formed, thereby increasing the efficiency of the check valve.

Reinforcement members can be provided in the flexible closure body to prevent the flexible closure bodies from being pressed through the cavities by the pressure present inside the control valve in the closed state. Such reinforcing members preferably extend in the axial direction or in the circumferential direction of the closure body, when opening in the circumferential direction is not impeded.

Preferably the frame is formed with two ring members extending in the circumferential direction. The ring members are spaced in the circumferential direction, connected to each other by a plurality of braces extending essentially in the axial direction, and the filter fabric extends between the ring members. By incorporating a filter function in the check valve, it is possible to suppress contaminant particles present in the hydraulic medium that may cause a failure of the control valve.

It is also proposed that a check valve provided for a pressure medium circulation system of a device for variably adjusting the valve timing of gas exchange valves in an internal combustion engine, and having a closed body and a valve seat arranged in an annular groove, is proposed. The object according to this is achieved by the sealing body being moved towards the valve seat only by the flow of the pressure medium during the closing process.

In another use of a check valve provided for a pressure medium circulation system of a device for variably adjusting the valve timing of gas exchange valves in an internal combustion engine, the check valve being arranged in an annular groove with at least one hermetically shaped closure body, The object according to the invention is that the check valve also comprises a frame in which one end of at least one closure body is received, and the check valve also has at least one stop which limits the closing movement of the closure body. Is achieved.

In this regard, the check valve can be arranged, for example, in a rotary joint for the pressure medium between the camshaft and the bearing bracket of the camshaft or in an annular groove of the control valve.

Further design space, by using a check valve disposed in an annular groove for the pressure medium circulation system of the device for variably adjusting the valve timing of the gas exchange valves in the internal combustion engine, according to any of the design schemes described above. Without the need for the check valve, the check valve can be integrated at different positions of the pressure medium circulation system in the internal combustion engine. In this regard, the check valve can be arranged, for example, in an annular groove of the control valve, or in a rotary joint for the pressure medium when the central control valve is arranged inside the variable adjustment device. When the check valve is arranged in the rotary joint, the pressure medium then reaches the supply connection of the control valve. In this regard, the rotary joint can be a rotary joint for a pressure medium between the camshaft and the bearing bracket of the camshaft.

By forming the check valves as described above, a simple and functionally safe assembly is ensured.

Further features of the invention are presented from the following description of the embodiments and from the drawings in which embodiments of the invention are schematically illustrated.

1A is a schematic diagram showing a very internal combustion engine very schematically.

1 is a longitudinal cross-sectional view of a device for changing the valve timing of an internal combustion engine having a pressure medium circulation system;

FIG. 2 is a cross-sectional view of the valve timing change device shown in FIG. 1 cut out along the cut line II-II.

3 is a longitudinal cross-sectional view showing the control valve cut away.

4 is a perspective view showing a first embodiment of a control valve according to the present invention.

FIG. 5 is a perspective view of the closure body of the control valve according to FIG. 4; FIG.

Figure 6a is a cross-sectional view cut away in the supply connection region of the control valve of the present application according to Figure 4 disposed in adjacent parts;

FIG. 6B is a cross-sectional view of the control valve similar to FIG. 6A.

FIG. 7A is a cross-sectional view similar to FIG. 6A but with a cut away control valve of the present disclosure having an improved closure body. FIG.

FIG. 7B is a cross-sectional view similar to FIG. 6B but with a cutaway view of the control valve of the present disclosure with a further improved closure body.

8 is a perspective view showing a second embodiment of a control valve according to the present invention.

9 is a perspective view partially cut away of the check valve of FIG. 8; FIG.

1A shows the internal combustion engine 100, with the piston 102 seated on the crankshaft 101 being shown in the cylinder 103. The crankshaft 101 is connected with the intake camshaft 106 or the exhaust camshaft 107 via respective transmission belt drive 104 or 105 according to the illustrated embodiment, and the gas exchange valves 110, 111. The first and second devices 1 for variably adjusting the valve timing of the < RTI ID = 0.0 > 1 < / RTI > Cams 108 and 109 of camshafts 106 and 107 actuate intake gas exchange valve 110 or exhaust gas exchange valve 111. Similarly, only one camshaft of the camshafts 106, 107 can mount the device 1, or only one camshaft 106, 107 with the device 1 may be provided.

1 and 2 show the hydraulic adjustment device 1a of the device 1 for variably adjusting the valve timing of the gas exchange valves 110, 111 in the internal combustion engine 100. This hydraulic adjustment apparatus 1a consists essentially of the stator 2 and the rotor 3 arrange | positioned concentrically with respect to this stator. The drive wheel 4 is fastened to the stator 2 in a spline manner and is formed as a chain sprocket according to the illustrated embodiment. Similarly, it is conceivable to design the drive wheel 4 as a belt drive device or a toothed gear drive device. The stator 2 is rotatably mounted on the rotor 3. The inner surface of the stator 2 is provided with five recesses 5 spaced in the circumferential direction according to the illustrated embodiment. The recesses 5 are formed by the stator 2 and the rotor 3 in the radial direction, by the two side walls 6 of the stator 2 in the circumferential direction, and by the first and second side surfaces in the axial direction. The range is limited by the cover parts 7 and 8. Each of the recesses 5 is closed to be pressure sealed in this manner. The first and second side cover parts 7, 8 are fastened with the stator 2 using the coupling members 9, for example using screws.

Wing grooves 10 extending in the axial direction are formed on the outer surface of the rotor 3, and wing portions 11 extending in the radial direction are disposed in the respective wing grooves 10. In addition, a wing 11 also extends into each recess 5, and the wings 11 are adjacent to the stator 2 in the radial direction, and the side cover parts 7, 8 in the axial direction. Adjacent to). Each wing 11 separates the recess 5 into two pressure chambers 12, 13 which function in opposition to each other. In order to ensure a pressure-sealing proximity of the wing 11 to the stator 2, a leaf spring member 15 is arranged in the wing grooves 10. This leaf spring member applies a force to the blade 11 in the radial direction.

Using the first and second pressure medium lines 16, 17, the first and second pressure chambers 12, 13 can communicate with the hydraulic pump 19 or the tank 18 via a control valve 14. Can be. By doing so, the adjustment apparatus which enables the relative rotation of the stator 2 facing the rotor 3 is formed. The control valve 14 has two working connections A and B. These working connections are in communication with the pressure medium lines 16, 17 via pressure medium channels. In addition, a tank connection T and a supply connection P are provided. Through the tank connection T, the control valve 14 is in communication with the tank 18. The supply connection P is then in communication with the hydraulic pump 19 using the pressure medium line 66. Using the operating unit 22, the control valve 14 can be moved to a number of control positions in which the various connections A, B, P, T are in communication with each other. In this regard, a configuration is provided in which all the first pressure chambers 12 are in communication with the hydraulic pump 19, and all the second pressure chambers 13 are in communication with the tank 18, or exactly the opposite. do. If the first pressure chambers 12 are in communication with the hydraulic pump 19 and the second pressure chambers 13 are in communication with the tank 18, the first pressure chambers 12 may be connected to the second pressure chambers ( 13) while decreasing. As a result, the wing 11 is displaced in the circumferential direction, that is, in the direction shown by the first arrow 21. Through the displacement of the vanes 11, the rotor 3 is rotated relative to the stator 2. Thereafter, a phase shift occurs between the cam shafts 106 and 107 and the crank shaft 101. Therefore, by supplying or discharging the pressure medium to the pressure chambers 12, 13 as desired, the valve timing of the gas exchange valves 110, 111 in the internal combustion engine 100 can be changed as desired. .

In addition, a control position is provided in which the two working connections A, B are only in communication with the supply connection P, or not with either of the supply connection P and the tank connection T. When the control valve 14 is located at such a control position, the phase position of the rotor 3 relative to the stator is fixed. (Valve timing variable adjustment) In order to prevent the pressure peak which generate | occur | produces in the apparatus 1 from reaching the hydraulic pump 19, between the hydraulic pump and the inside of the control valve 14, as will be described later in the following. A check valve is provided.

3 schematically shows a longitudinal cross-sectional view of the control valve 14 cut away. The control valve 14 is composed of a valve housing 41 and a control piston 42. The valve housing 41 is formed essentially in a hollow cylindrical shape, and on the outer surface of the valve housing three annular grooves 43, 44, 45 are formed axially spaced. Each of the annular grooves 43-45 represents a connection of the control valve 14. And the (first and third) annular grooves 43, 45 located externally in the axial direction form working connections A, B, and the (second) annular groove 44 located centrally The supply connection part P is formed. The tank connection portion T is formed by an opening provided in the front end surface of the valve housing 41. Each of the annular grooves 43-45 is in communication with the interior of the valve housing 41 through the first radial opening 46. Inside the valve housing 41, a control piston 42, which is formed essentially in a hollow cylinder, is disposed axially displaceable. The control piston 42 is forced by the spring member 47 at the tip end face and by the push rod 48 of the operating unit 22 at the opposite tip face. By supplying current to the operating unit 22, the control piston 42 can be displaced to any position between the first and second end stops 49, 50 against the force of the spring member 47. .

The control piston 42 is provided with the 1st and 2nd ring land parts 51 and 52. As shown in FIG. The outer diameter of the ring land portions 51 and 52 is formed to match the inner diameter of the valve housing 41. A fourth annular groove 57 is formed between the ring land portions 51, 52 in the control piston 42. Further, in the control piston 42, a second radial opening 46a is formed between the front end face of the control piston on which the push rod 48 acts and the second ring land portion 52, thereby controlling The interior of the piston 42 is in communication with the interior of the valve housing 41. The first and second ring land portions 51, 52 are provided with the supply connection part P and the working connection parts A, depending on the position of the control piston 42 with the control edge part 53 relative to the valve housing 41. The communication between B) is formed in such a way that it can be opened or blocked through the fourth annular groove 57 and is arranged on the outer surface of the control piston 42. At the same time the communication between the working connections A, B and the tank connection T is also opened or blocked. By influencing the position of the control piston 42 inside the valve housing 41, a pressure medium is supplied to the first or second pressure chambers 12, 13 as desired, and each other pressure chamber Can be discharged from the fields 12 and 13. By doing so, the phase positions of the cam shafts 106 and 107 relative to the crankshaft 101 can be changed as desired.

4 shows a control valve 14 according to the invention in a perspective view. Also shown is the valve housing 41, the operating unit 22, and the closure body 58 of the check valve 54. The closure body 58 is disposed in the second annular groove 44 and consists of only a very flexible rigid material, such as plastic. Between the operating unit 22 and the valve housing 41, an assembly flange 70 with a bore is provided, by which the control valve 14 is fixed to an adjacent part (not shown in FIG. 4). Can be.

5 shows a perspective view of the closure body 58. The sealing body is composed of a blocking body 59 having a sealing surface 60 and guide members 61. And the guide members are formed as guide webs in the illustrated embodiment. In addition, the blocking bodies 59 are formed with flow surfaces 62, which protrude beyond the guide members 61. Guide members 61 are formed with through-flow openings 64 and fixing members formed as latch nose portions 63.

6A and 6B show a control valve 14 according to the invention in a cross-sectional view similarly to the diagram shown in FIG. 4. In this case the cutting plane is located in the region of the feed connection P. The control valve 14 is mounted to the adjacent component 65 in the figure. A pressure medium line 66 is formed in the adjacent part 65, which pressure medium line 66 communicates the second annular groove 44 with a hydraulic pump (not shown). The pressure medium line 66 communicates with the second annular groove 44 through an opening 67 formed in the wall portion of the adjacent part 65.

The sealing body 58 is disposed in the second annular groove 44 in such a way that the sealing surface 60 of the blocking body 59 is oriented in the direction of the opening 67.

The groove bottom 68 of the second annular groove 44 has two horizontal straightening portions 69, the horizontal straightening portions of which the guide members 61, which are formed as guide webs, have a sealing body 58. In the assembled state is formed in a manner adjacent to the horizontal correction portion. The horizontal straightenings 69 are therefore used as a guide surface for the closure body 58.

The horizontal straightenings 69 are arranged oriented as defined by the bore of the assembly flange 70. By doing so, the horizontal corrections, on the one hand, fulfill the function that the sealing body 58 is correctly oriented towards the opening 67 and mounted in the valve housing 41. The assembly flange 70 presets the orientation of the valve housing 41 inside the adjacent part 65, and the horizontal corrections 69 adjust the orientation of the blocking body 59 in the second annular groove 44. Set in advance.

In addition, while the internal combustion engine 100 is in operation, the guide members 61 perform a guide function, whereby the closure body 58 can only be moved in the radial direction of the valve housing 41.

6A shows the check valve 54 in the open state. The pressure medium entering the second annular groove 44 through the opening 67 is in close contact with the blocking body 59 and thus the sealing body 58 towards the groove bottom 68 of the second annular groove 44. Let's do it. The pressure medium can then reach the interior of the valve housing 41 through the second annular groove 44, the through-flow openings 64, and the first radial openings 46.

In contrast to the above, in the pressure medium flow flowing from the inside of the valve housing 41 in the direction of the opening 67, the pressure medium flows to the back surface and the flow surfaces 62 of the blocking body 59. By doing so, the closure body 58 is moved in the direction of the opening 67 until it is guided by the guide members 61 and adjoining the wall portion of the adjacent part 65. The state where the check valve 54 is blocked in this way is shown in Fig. 6B. In this state, the opening 67 is blocked by the blocking body 59 so that the pressure peak present in the (variable adjustment) device 1 cannot be transmitted to the hydraulic pump through the pressure medium line 66. do.

In the state of such a check valve 54, the latch nose portions 63 adjoin the groove bottom 68 of the second annular groove 44. Therefore, while carrying the control valve 14, the latch nose portions 63 are used as loss preventing portions. And even when assembling, the latch nose portions 63 serve to prevent the blocking body 59 from protruding beyond the edge of the second annular groove 44. Therefore, it is ensured that the blocking body 59 is not damaged or broken while the control valve 14 is assembled in the adjacent part 65, and that the control valve 14 is fixed in the adjacent part 65.

FIG. 7a shows a control valve 14 according to the invention similar to FIG. 6a but with an improved closure body 58. Unlike the above-described embodiments, in the present embodiment, the guide members 61 and the corresponding horizontal correctors 69 formed as guide webs are arranged at a predetermined angle to each other. Thus, preferably the closure body 58 can be oriented in exactly one direction and mounted in the second annular groove 44. And orientation errors of the closure body 58 are excluded.

FIG. 7B shows a control valve 14 according to the invention similar to FIG. 6B but with a further improved closure body 58. In this case, the guide member 61 is formed as the journal portion 71. This journal portion 71 is disposed at the center of the rear surface of the blocking body 59. The journal portion 71 is inserted into and engaged with one of the first radial openings 46 of the second annular groove 44. The ring-shaped wall portion 69a of the radial opening 46 is then used as a guide surface for the closure body 58. In order to ensure the correct orientation of the closure body 58 during assembly, the radial openings 46 which are preferably designated for guiding the closure body 58 are formed larger than the remaining radial openings 46. And journal portion 71 is formed to conform to the dimensions of the larger radial openings 46. In order to ensure a secure closure of the check valve 54, the outer surface of the journal portion is preferably formed in the form of a profile. In so doing, the pressure medium can flow through the radial opening 46 containing the journal portion 71 and flow into the blocking body 59.

At the end portion of the journal portion 71 facing away from the blocking body 59, a bead portion 72, which is formed in a ring shape and used as a fixing member, is provided to the journal portion 71. As shown in FIG.

Of course, in addition to arranging the sealing body 58 in the second annular groove 44 between the valve housing 41 and the adjacent part 65, a fourth annular between the control piston 42 and the valve housing 41 is also present. It is also conceivable to arrange the closure body 58 inside the groove 57. This can be implemented, for example, in the embodiment described in JP 07-229408 with respect to the control valve 14.

8 shows a further embodiment according to the invention of a control valve 14 with another variant of the check valve 54. 9 shows the check valve 54 partially in perspective view. The check valve 54 consists of a rigid frame 73 and two flexible closure bodies 58.

The frame 73 includes two ring shaped sections 74. These ring-shaped sections are connected to each other through a plurality of braces (75). The braces 75 are separated from each other by a plurality of cavities 76 spaced circumferentially. The extension of the frame 73 provided in the axial direction corresponds to the extension of the second annular groove 44. By doing so, it is ensured that the frame 73 adjoins in a pressure sealed manner to the ring surface which defines the second annular groove 44, so that the pressure medium flow can only be made through the cavities 76. The frame 73 also extends circumferentially along the entire second annular groove 44. Two flexible closure bodies 58 are arranged in the radial direction inside the brace 75. Each hermetic body 58 is formed as a band curved in a ring shape, which extends circularly along the entire inner circumferential surface of the frame 73. Each axial side of the closure body 58 is received in the frame 73 and securely fastened to the frame. This can be realized, as shown in the figure, by using form fixing means, or by partially casting the closure body 58, for example when manufacturing the frame 73. According to a preferred embodiment, the closure body 58 is formed as a silicone sealing lip which is injection molded directly into the frame by a two-component injection molding method.

The operation method of the check valve 54 is described below. When the pressure medium flows into the control valve 14, the flexible closure bodies 58 are in close contact in the radial direction inward, thereby opening the cavities 76.

When the pressure medium flows in the opposite direction, the sealing bodies 58 are pressed against the braces 75, thereby closing the cavities 76 while adjoining each other.

In addition, reinforcing bars 77 may be provided in the sealing bodies 58. These reinforcing bars prevent the sealing bodies 58 from being pressed through the cavities 76. The reinforcement bars 77 are preferably circumferentially oriented so that they do not interfere with the opening of the sealing bodies 58.

For the above embodiment for the check valve 54, the cavities 76 may have a filter fabric 78. The filter fabric may be cast within, for example, the frame 73 during manufacture. By doing so, the function of the ring filter and the function of the check valve 54 can be integrated inside one structural member. Filter fabric 78 is shown only in one of the cavities 76 for reasons of clarity shown in FIG. Of course, to meet the filter function, the filter fabric is provided in all cavities 76.

As the check valve 54 is formed according to any one of the embodiments described above, the check valve 54 is preferably arranged inside the annular groove 44 of the control valve 14, As a result, no additional design space is required. The check valve 54 can be simply mounted, thereby ensuring that the function of the check valve 54 is not degraded during the assembly of the control valve 14. It is also conceivable to design all embodiments as plastic injection molded parts with integrated filter functions.

<Reference list>

1: (valve timing variable adjustment) device

1a: control unit

2: stator

3: rotor

4: driving wheel

5: recess

6: side wall

7: first side cover

8: second side cover

9: coupling member

10: wing groove

11: wing

12: first pressure chamber

13: second pressure chamber

14: control valve

15: leaf spring member

16: first pressure medium line

17: second pressure medium line

18: tank

19: hydraulic pump

21: arrow

22: operating unit

41: valve housing

42: control piston

43: first annular groove

44: second annular groove

45: third annular groove

46: first radial opening

46a: second radial opening

47: spring member

48: push rod

49: first end stop

50: second end stop

51: first ring land portion

52: second ring land portion

53: control edge

54: check valve

57: fourth annular groove

58: sealed body

59: blocking body

60: sealing surface

61: guide member

62: flow surface

63: latch nose portion

64: through-flow opening

65: adjacent parts

66: pressure medium line

67: opening

68: groove bottom

69: flattening

69a: wall

70: assembly flange

71: journal

72: bead

73: frame

74: ring-shaped section

75: brace

76: joint

77: stiffening bar

78: filter fabric

100: internal combustion engine

101: crankshaft

102: piston

103: cylinder

104: power transmission belt drive

105: electric drive belt drive

106: intake camshaft

107: exhaust camshaft

108: cam

109: cam

110: intake gas exchange valve

111: exhaust gas exchange valve

P: supply connection

T: tank connection

A: first working connection

B: second working connection

Claims (18)

delete delete delete delete delete A control valve 14 for the apparatus 1 for variably adjusting the valve timing of the gas exchange valves 110, 111 of the internal combustion engine 100, A valve housing 41 disposed inside the adjacent part 65, A control piston 42 disposed inside the valve housing 41, The valve housing 41 is formed with an annular groove 44 extending in the circumferential direction of the valve housing and flowing through the pressure medium, A control valve (14) comprising a check valve (54) having at least one hermetically shaped body (58) which is flexible and arranged in an annular groove (44), The check valve 54 also comprises a frame 73 which conforms to the shape of the annular groove 44, in which one end of at least one sealing body 58 is received, and also the check valve 54 Control valve, characterized in that it has at least one stop (74, 75) to limit the closing movement of the closure body (58). 7. The sealing body (58) according to claim 6, wherein the sealing body (58) consists of a band curved in a ring shape and extends in the circumferential direction, and an axial end formed in the ring shape of the sealing body (58) is received in the frame (73). Control valve 14, characterized in that. 7. A closure is provided according to claim 6, wherein two closure bodies (58) are arranged which are offset from one another in the axial direction, and each end of each closure body (58) is received in the frame (73), and the frame Control valves (14), characterized in that the ends received in (73) are ends facing away from the other closure body (58), respectively. 7. Control valve (14) according to claim 6, characterized in that the two closure bodies (58) are arranged and formed in such a way that they overlap each other in the axial direction with the check valve (54) shut off. 7. The frame 73 according to claim 6, wherein the frame 73 is formed with two ring members extending in the circumferential direction, which ring members are connected to each other by a plurality of braces spaced in the circumferential direction and essentially extending in the axial direction. And a filter fabric extending between the ring members. Control valve (14) according to claim 6, characterized in that the flexible closure body (58) has reinforcing members (77) extending in the circumferential direction or in the axial direction. Control valve (14) according to claim 6, characterized in that the axial extension of the frame (73) is formed in conformity with the axial extension of the annular groove (44). delete delete delete A check valve 54 provided for the pressure medium circulation system of the apparatus 1 for variably adjusting the valve timing of the gas exchange valves 110, 111 of the internal combustion engine 100, and disposed in the annular groove 44, A check valve (54) comprising at least one hermetic body (58) formed flexibly, The check valve 54 also comprises a frame 73, in which one end of the at least one closure body 58 is received, and the check valve 54 is also a closure body 58. Check valve (54), characterized in that it has at least one stop (74, 75) for limiting the closing movement of. 17. The check valve according to claim 16, characterized in that the check valve 54 is arranged in a rotary joint provided for the pressure medium between the cam shafts 106 and 107 and the bearing brackets of the cam shafts 106 and 107. 54). 17. The check valve (54) according to claim 16, wherein the check valve (54) is arranged in an annular groove (44) of the control valve (14).

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